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Recently we had the situation that the Veritas cluster (InfoScale 7.3) showed interfaces as down on the two RedHat 7.3 nodes. This e.g. can happen when you change hardware. Although all service groups were up and running this is a situation you usually want to avoid as you never know what happens when the cluster is in such a state. When you have something like this:

In our configuration eth1 and eth3 are used for the interconnect and bond0 is the public network. As you can see above the eth1 and bond0 are reported as down for the second node. Of course, the first check you need to do is to check the interface status on the operating system level, but that was fine in our case.

Veritas comes with a tiny little utility (dlpiping) you can use to check connectivity on the Veritas level. Using the information from the lltstat command you can start dlpiping in “send” mode on the first node:

[root@xxxxx-node1 ~]$ /opt/VRTSllt/dlpiping -vs eth1

When that is running (will not detach from the terminal) you should start in “receive” mode on the second node:

[root@xxxxx-node1 ~]$ /opt/VRTSllt/dlpiping -vc eth1 xx:xx:xx:xx:xx:xx
using packet size = 78
dlpiping: sent a request to xx:xx:xx:xx:xx:xx
dlpiping: received a packet from xx:xx:xx:xx:xx:xx

This confirms that connectivity is fine for eth1. When you repeat that for the remaining interfaces (eth3 and bond0) and all is fine then you you can proceed. If not, then you have another issue than what we faced.

The next step is to freeze all your service groups so the cluster will not touch them:

[root@xxxxx-node1 ~]$ haconf -makerw
[root@xxxxx-node1 ~]$ hagrp -freeze SERVICE_GROUP -persistent # do that for all service groups you have defined in the cluster
[root@xxxxx-node1 ~]$ haconf -dump -makerw

Now the magic:

[root@xxxxx-node1 ~]$ hastop -all -force

Why magic? This command will stop the cluster stack on all nodes BUT it will leave all the resources running. So you can do that without shutting down any user defined cluster services (Oracle databases in our case). Once the stack is down on all the nodes stop gab and ltt on both nodes as well:

When doing a performance review I often do talk with the DBA about the CPU utilization of the server. How reliable is the server CPU utilization with tools like top or the host CPU utilization in the AWR-report? E.g. on an Linux Intel x86-64 server with 8 Cores and 16 logical CPUs (Intel Hyperthreading), what does a utilization of 50% mean?
As I had an ODA X7-M in a test lab available, I thought I’ll do some tests on that.

In my old days at Oracle Support we used a small script to test the CPU single thread performance of an Oracle DB-server:

set echo on
set linesize 120
set timing on time on
with t as ( SELECT rownum FROM dual CONNECT BY LEVEL <= 60 )
select /*+ ALL_ROWS */ count(*) from t,t,t,t,t
/

The SQL just burns a CPU-Core for around 20 seconds. Depending on your CPU single thread performance it may take a bit longer or completes faster.

On the ODA X7-M I have 16 Cores enabled and as hyperthreading enabled I do get 32 CPUs in /proc/cpuinfo:

When running with 16 Jobs top showed a utilization of around 50-52%. However running more than 16 Jobs showed an increase of the average time a job takes. I.e. with 16 Jobs the 16-Cores-Server is already almost fully utilized. Running with 32 Jobs results in an average elapsed time of 1.9 times compared to running 16 jobs (or less) concurrently. As it is 1.9 times and not 2 times I can conclude that there is an advantage of running with hyperthreading enabled, but it’s only around 5-10%.

So when calculating the utilization of your server then base it on the number of cores and not on the number of threads. When looking at your host CPU-utilization in top or in the AWR-report on an hyperthreaded-enabled server then it’s a good idea to multiply the server-utilization by 1.9.

2018 is yet another great year for developers! Oracle’s awesome global developer conference series, Oracle Code, is back – and it’s bigger and better!

In 2017 Oracle ran the first series of Oracle Code developer conferences. In over 20 cities across the globe the series attracted more than 10,000 developers from all over the world, providing them with the opportunity to learn new skills, network with peers and take home some great memories. Following the huge success, Oracle is about to run yet another 14 events across the globe kicking off in late February in Los Angeles. The great thing about Oracle Code, attendance and speaking at the conferences is fully free of charge, showing Oracle holding true to the commitment to the developer communities out there. Across four continents you will get to hear everything that is hot and top in the industry: Blockchain, Containers, Microservices, API Design, Machine Learning, AI, Mobile, Chatbots, Databases, Low Code Development, trendy programming languages, CI/CD, DevOps and much, much more will be right in the center of Oracle Code.

Throughout the one-day events, that provide space for 500 people, developers can share their experience, participate in hands-on labs, talk to subject matter experts and, most importantly, have a lot of fun in the Oracle Code Lounge.

Create your own sculptures and furniture with the 3D printer and help complete the furniture created using Java constructive geometry library. The Oracle technology used is Application Container Cloud running Visual IDE and Java SE running JSCG library.

Oracle Zip Labs Challenge

Want some bragging rights and to win prizes at the same time? Sign up for a 15-minute lab on Oracle Cloud content and see your name on the leaderboard as the person to beat in Oracle Zip Labs Challenge.

IoT Workshop

Interact and exchange ideas with other attendees at the IoT Workshop spaces. Get your own Wi-Fi microcontroller and connect to Oracle IoT Cloud Service. Oracle Developer Community is partnering with AppsLab and the Oracle Applications Cloud User Experience emerging technologies team to make these workshops happen.

Robots Rule with Cloud Chatbot Robot

Ask NAO the robot to do Tai Chi or ask "who brewed the beers"? So how does NAO do what it does? It uses the Intelligent Bot API on Oracle Mobile Cloud Service to understand your command and responds back by speaking back to you.

Dev Live

The Oracle Code crew also thought of the folks who aren’t that lucky to participate at Oracle Code in person: Dev Live are live interviews happening at Oracle Code that are streamed online across the globe so that everyone can watch developers and community members share their experiences.

Recently Oracle announced new AI-based Apps for Finance Leaders to empower CFOs w/ data-driven insights to adapt to change, develop new #markets & increase profitability! With Oracle Adaptive Intelligent Applications for ERP, finance leaders can benefit from: Better insight: Making use of analytics and synthetic intelligence to finance can enhance efficiency and will increase agility […]

Below a workaround is shown how to “duplex” archivelog backups between disk and tape:

Backup on disk (normal way):

backup device type disk archivelog all;

Immediately backup on tape:

backup device type sbt archivelog until time 'sysdate' not backed up 2 times;

This backup command backs up all archivelogs, that are not backed up twice, so all which are backed up with the first command. As in the first backup command a logfile switch is included, between the two backup commands, no logfile switch should occur, otherwise “duplexing” does not work. The until time clause in the second command is added to prevent RMAN from another logfile switch, which would lead to different contents of the backups. And this clause does not filter anything, because sysdate means date and time when issuing the command.

Hi Tom
We have an anonymous pl/sql block which looks like follows but using dbms_sql (the following doesnt work)
declare
vRows number;
begin
for i in (select * from user_tables)
loop
select count(*)
into vRows
from i....

Hi Team,
I have scenario in which I need to check which of my procedures(they run in batch) are slowing down the operations.
The procedure consist of two main tasks:
1.) Get data from multiple table (has multiple joins and vast data)
2.) insert ...

<code>create or replace procedure fetch_ids(ename in varchar2,hiredate in date)
as
begin
select * from emp where empname=ename and join_date=hiredate ;
end;</code>
Problem statement:
1)if i will not pass the ename, i need to fetch all the e...

Hi Tom,
I have a very huge data aggregation which should be ideally done on a OLAP database using cube. Due to some contrains, I am doing it in my transactional database.
When I ran the SQL with multiple table joins, the SQL errored out due to...

Hi Tom,
I have about 25 MV's in my production application. Mostly in two refresh groups. Very few stand alone.
One group (lets call it GROUP-A) refreshes every minute as a business requirement and the other (GRIOUP-B) every hour. Few more MV's ev...

Hi:
I want to clean some space about some tables ,there are a few ways ,such as move ,shrink and impdp.
I want to know which one is better regardless of space consideration and assume this tables can use all those methods.
Can you answer my...

My company has select MS Active Directory for the enterprise directory services. We would like to integrate our Oracle networking with AD, in lieu of TNSNAMES or Oracle Names, for database connection resolution. However, we are having a hard time f...

Hi Tom,
If the primary key on a index-organized table is not incremental, wouldn't this create bottlenecks as data volume grows under OLTP loads?
Wouldn't the data being inserted needed to be sorted and inserted in the middle of the leaves?
Woul...

I'm trying to create a generic before update trigger
which will compare all :old.column_values to all
:new.column_values. If the column_values are different, then I
would like to log the change to a separate table. When I try to
compile :ol...

Hi Tom,
We have a table with a non incremental composite key of (dialaog_id, insertion_date).
This creates problems since we have insertions in the middle of the leaves. Data has to be relocated.
We cannot use incremental keys since this cre...

Hi,
I want to transfer data between test systems, version is Oracle Database 12c Release 12.1.0.1.0 - 64bit Production.
I wrote scripts for a full export and import (expdp/impdp)
When importing I get many errors because objects do not exist...